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    <script>
        // var fn = function (){
        //     console.log("我");
        //     var d
        // }
        // fn()
        // console.log(d);
        // a(1,1) 
        // function a(a,b,c){
        //     console.log(a,b,c);
        // }
        function sum(a,b,c) {
            var s1 = a + b + c
            return s1 
        }
        
        var res = sum(1,2,3)
        console.log(res);
    </script>
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